The invention relates to a coupling or connection device for control elements, particularly rods, Bowden cables, or the like which are required to be mutually connected.
A coupling device of this type is intended primarily for motor vehicles, in order to adjustably connect Bowden cables, rods or similar control elements which are provided to actuate the flaps of a heating apparatus. As a general rule it is difficult to assemble the control elements due to constricted space conditions. It is particularly a problem to adjust the flaps with the required precision, whilst the fresh air flaps to be actuated, which are required to close absolutely fluid-tightly in one position, frequently cannot be adjusted sufficiently accurately, compare German Published Unexamined Patent Application (DE-OS) No. 24 05 321.
A coupling device of the type initially mentioned is described in German Patent Application No. 47a 3-G 82, which is suitable for connecting two rods, each of which exhibits an angled end. The connecting element in this case is tripartite. It exhibits for each angled rod end a bored nipple, the bore of which merges at one end into a radial slot which serves to accommodate the angled end. Each nipple is provided with a male screw-thread, by which it is engageable into an associated sleeve provided with a female screw-thread on both sides, after the insertion of the angled ends of the rods. This coupling device serves for the permanently firm coaxial connection of rods, although no adjustability of the length of the rods so connected would be possible here. In the one axial direction the angled rod ends strike the radial slot of the respective nipple. In the opposite axial direction, that is to say in the slide-in direction of the rods into the coupling device, the rods strike with the angled end axially against an internal web of the sleeve which subdivides the screw-threaded bore of the sleeve into two bore sections. If a length adjustment were to be attempted by loosening the nipple, then this leads to axial play of the rod between the web of the sleeve on the one hand and the radial slot of the nipple on the other hand. For these reasons the known coupling device is unsuitable for the length adjustment of the two rods connectable in this manner.
An underlying object of the invention is to develop a coupling device of the generic type referred to above, which, whilst having a particularly simple construction, permits a precise length adjustment of the control elements to be mutually connected by it.
This object is achieved according to the invention, by providing a threaded connection at one end of the connecting element and by providing an anchoring ring groove in a bore at the other end of the connecting element, the ring groove serving to anchor a first control element with relative rotation of the first control element and the connecting element being permitted to accommodate threaded adjustment of the connection at a second control element.
The coupling device according to the invention possesses the following advantages. It is particularly simple, economical of space and inexpensive. It permits a precise adjustment of the length of the control elements connected to it, and thus, in a simple manner a highly precise adjustment of flaps or similar parts which have to be actuated by means of the control elements. A subsequent adjustment and readjustment is also possible. Another advantage is the possibility of a direct articulation of the flaps without intermediate lever, auxiliary lever, and the like. The adjusting movement is effected in simple manner by rotating the connecting element relative to the control elements.
An advantageous further development results with especially preferred embodiments which have a housing cover part. Here the cover part may be a separate, removable and reattachable part of the connecting element, whilst the cover part permits the engagement of a control element into the bore and adjoining ring-shaped groove, the coupling part of which exhibits the angled end. A connecting element formed in this way, as a plastic part, for example, is particularly simple, light, economical of space and inexpensive.
Especially preferred embodiments include simple snap connection devices for the housing cover part. Also, the bores and grooves for accommodating connection of the connecting element to the control elements are dimensioned to permit the insertion of the angled bent end in a simple manner.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.